When you live in an apartment building that has its own washer and dryer, and you have a lot of clothes to wash, PLEASE, PLEASE, PLEASE be vigilant about taking your clothes out when the loads are done just on the off chance that someone else in the building also finds it necessary to do laundry. It's one of the easiest things in the world to set a timer or watch the clock to know when the laundry is done. (Hint: the machines in our building take 30 minutes to wash and 45 minutes for one dry cycle.)
As a corollary: out of common courtesy, don't wait a whole month to do your laundry and expect to monopolize the machines an entire day. Some of us do laundry on a weekly basis in part so we don't overload the building's capacity. In fact, when I have a more than normal amount of laundry to do, I go to the laundromat down the street.
Corollary #2: This applies especially when the building has only one washer and one dryer.
Corollary #3: This might not apply to tenants who have children. I imagine with children, the amount of laundry increases almost exponentially and the would-be launderer probably doesn't have any choice. But when there are zero (0) people with children in the building, it's inexcusable to let the laundry pile up in between beer runs and "DJ night" upstairs (when, for some inexplicable reason, my neighbors play what sounds like the "Super Terrific Chicago Night Dancing Party").